VERTEBRAL PSEUDARTHROSIS ASSOCIATED WITH DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS

Diffuse idiopathic skeletal hyperostosis is an ossifying diathesis tha t commonly affects the vertebral skeleton. Spinal ankylosis can occur, predisposing the spine to abnormal stresses and fracture. Fracture th rough an ankylosed segment with continued motion at the site of fractu re can result in pseudoarthrosis. Pseudoarthrosis can also develop at the junction of the fused and mobile spine secondary to chronic abnorm al stresses. This complication is manifest radiographically by single- level intervertebral disc space destruction, vertebral endplate erosio ns, marked vertebral sclerosis, and large osteophytes. The radiographi c manifestations can mimic infective spondylitis or neuropathic change s.